1. Field of the Invention
This invention relates to an applicator or coating device for dispensing a liquid medium in the forming of a solid three-dimensional article wherein the liquid medium is capable of solidification when subjected to prescribed energy, and more particularly to a specially configured applicator bar for dispensing the liquid medium in relatively thin layers of uniform thickness for the successive solidification thereof, so as to form the article in a very precise manner.
2. Description of the Prior Art
In general, apparatus for forming a solid three-dimensional article from a liquid medium capable of solidification when subjected to prescribed energy are known in the prior art. For example, U.S. Pat. No. 2,755,578 to O. J. Munz discloses a system for generating three-dimensional objects from a liquid medium by irradiating liquid layers with the aid of a computer programmed irradiation source and a translational mechanism. Other arrangements of this general type are disclosed in an article by H. Kodama, entitled "Automatic Method for Fabricating a Three-Dimensional Plastic Model With Photo-Hardening Polymer," Review Scientific Instruments, Vol. 52, No. 11, November 1981, pages 1770-1773, and an article by A. J. Herbert, entitled "Solid Object Generation," Journal of Applied Photographic Engineering 8 (4), August 1982, pages 185-188. A similar arrangement is disclosed in reexamined U.S. Pat. No. 4,575,330 to C. W. Hull, in which Reexamination Certificate B1 4,575,330 was issued on Dec. 19, 1989. Other prior art of interest includes the U.S. Pat. Nos. 2,525,532 to Dreywood, 2,381,234 to Symmes, 3,723,120 to Hummel, 3,609,707 to Lewis et al., 4,081,276 to Crivello and 4,252,514 to Gates, and the British Patent No. 566,795 to Gates.
However, a need still exists for a method of and apparatus for forming a solid three-dimensional article from a liquid medium in an accurate, rapid and expeditious manner, with a minimum of waste in time and material, and a primary purpose of this invention is to provide such a method and apparatus.